Pipetting fluid for chemical analysis has been known for some time. Automated pipetting of fluids is a more recent trend. Automated pipetting includes precision metering of fluids. To aspirate one fluid while simultaneously dispensing another with one single device has been an elusive problem in this field.
The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
U.S. PATENT DOCUMENTSU.S. PAT. NO.ISSUE DATEINVENTOR1,135,476Apr. 13, 1915Watts1,170,958Feb. 8, 1916Butler1,499,662Jul. 1, 1924Jubé1,850,132Mar. 22, 1932Morse2,028,161Jan. 21, 1936Mann2,062,285Dec. 1, 1936Bergman2,093,344Sep. 14, 1937Wandel2,410,808Nov. 12, 1946Christensen3,426,657Feb. 11, 1969Bimba3,464,359Sep. 2, 1969King, et al.4,065,230Dec. 27, 1977Gezari4,089,624May 16, 1978Nichols, et al.4,242,058Dec. 30, 1980Zakora4,457,747Jul. 3, 1984Tu4,481,946Nov. 13, 1984Altshuler, et al.4,486,188Dec. 4, 1984Altshuler, et al.4,695,431Sep. 22, 1987Farrell4,898,579Feb. 6, 1990Groshong, et al.4,941,808Jul. 17, 1990Qureshi, et al.5,328,459Jul. 12, 1994Laghi5,366,904Nov. 22, 1994Qureshi, et al.5,407,424Apr. 18, 1995LaFontaine, et al.5,492,535Feb. 20, 1996Reed, et al.5,529,463Jun. 25, 1996Layer, et al.5,540,562Jul. 30, 1996GiterFOREIGN PATENT DOCUMENTSPATENT NO.COUNTRYPUBLICATION DATEAPPLICANT706,280FRJun. 20, 1931Denoncourt
The prior art listed above, but not specifically discussed, teach other devices for pumping or displacing fluids and further catalog the prior art of which the applicant is aware. These references diverge even more starkly from the references specifically distinguished above.